Method and apparatus for data transfer across a network

Abstract

Provided are methods, computer programs and apparatus for communication in a distributed object-oriented data processing environment. Requests for retrieval of data items from another data processing apparatus include embedded objects having executable class functions for performing operations at the target data processing apparatus. This has the advantages of the request implicitly sending data as well as requesting data and allows the request to perform a test on data within an object. Objects within the request can be embedded within each other with different encryption and compression applied to the different objects. As well as achieving communication efficiencies, the ability to selectively encrypt components of a request can be used to provide greater security. For example a store may be able to interpret the request, but credit details may be separately encrypted such that only a bank can decrypt that subcomponent of the request.

1. An object-oriented data processing environment that includes a first data processing apparatus and a second data processing apparatus for managing communications between the first data processing apparatus and the second data processing apparatus, the object-oriented data processing environment comprising:
 means for creating a request to send from the first data processing apparatus to the second data processing apparatus to retrieve an item from a second data processing apparatus and send the item to the first data processing apparatus, including program code for instantiating a first object class to generate a first object for inclusion within said request, the generated first object comprising an executable class function for applying a test condition to target data that is stored in a target data processing object that is included in the second data processing apparatus; 
 means, responsive to receipt of the generated first object at the second data processing apparatus, for executing the class function to apply the test condition to test the target data; 
 the second data processing apparatus including means for testing the target data to determine whether or not the item can be retrieved from the second processing apparatus; 
 the second data processing apparatus including means for generating a positive reply to the item request in response to a positive result from the test, and means for sending the positive reply to the first data processing apparatus; 
 wherein the first object instantiates a class which includes a class function for encoding the first object for transmission from the first data processing apparatus to the second data processing apparatus, and a class function for restoring itself when received at the second data processing apparatus; 
 wherein, responsive to attributes having been set for the first object, said encoding of the first object is performed in accordance with said attributes; and 
 wherein a first sender computer program at the first data processing apparatus is responsible for sending the first object, the first sender computer program being responsive to said set attributes to create an attributes object and to associate the attributes object with the first object.